The invention relates to a mold-closing unit for an injection molding machine for processing plastics materials and other plasticizable masses such as e.g. plastics materials, powdery masses or ceramic masses.
A mold-closing unit of this kind is known from DE 43 40 693 C2 and serves substantially to move the mobile mold carrier towards the stationary mold carrier in order thereby to close the mold. Apart from the piston-cylinder unit necessary for this movement, two pressure cylinders are also provided there to build up the locking pressure during the injection process. In order to render possible a central arrangement of the hydraulic block, without additional lines having to be led to the individual consumers, the support element for the mold-closing unit is inserted there simultaneously as a distributor for the hydraulic medium. In order, however, not to disrupt there the support effect of the support element, there is allocated to the support element a separate hydraulic block which is disposed on the support element. In order, therefore, to make distribution of the hydraulic medium possible, comparatively long bores are necessary inside the support element.
Proceeding from this prior art, the object underlying the present invention is to develop a mold-closing unit of the type mentioned initially in such a way that a more compact construction of the mold-closing unit is realized with shortening of the bores for the hydraulic lines.
This object is achieved by a mold-closing unit with the features of claim 1.
Now the support element of the mold-closing unit consists of a plurality of support sections which accommodate the hydraulic block between them. In order to achieve nevertheless a certain inner stability, the support sections and the hydraulic block are connected to one another via fastening means. The support sections themselves can be configured more simply in that only functional bores, i.e. bores which are actually required for the transmission of hydraulic medium, have to be introduced since, as a result of the smaller dimensions, correspondingly precise bores can also be bored from one side only. With the arrangement of the hydraulic block between the two support sections, not only can flexible lines be dispensed with, but the latter can also be shortened; both of these being advantages which have a positive effect on the control of the mold-closing unit. The break-up of the previous support element, however, also makes possible the use of different materials for the more severely loaded support sections and the generally less stressed hydraulic block. The materials can, therefore, be paired with one another from the viewpoints of simplification of manufacture and of static dimensioning. Simultaneously, through this distribution, the pre-requisites for increased modularity are created using one and the same hydraulic distributor in conjunction with support sections of the most varied kind.
If the support sections, in an embodiment according to claim 3, are designed symmetrically, this also contributes to increasing modularity, since identically constructed simple parts can be exchanged as necessary. Simultaneously the transporting of replacement parts is made simpler even to distant countries.
In an embodiment according to claims 4 and 5, a flow of force arises such that forces are substantially transmitted inside the respective connecting section, without there being any more serious stressing in the region of the hydraulic block on which forces impinge possibly in an embodiment of the balancing cylinder according to claim 8.
The desired modularity can, in an embodiment according to claim 6, be further increased in that the hydraulic block has at its disposal connecting regions which co-operate with connecting regions of the connecting sections, the appearance of the connecting sections in other respects being unimportant. Thus the hydraulic block fits with any connecting section insofar as the latter only has the suitable connecting region, which both reduces costs of production and also contributes to reducing storage at the manufacturers in respect of the hydraulic block.